Ariel Castro, who was convicted last month on charges related to the capture and imprisonment of three women in Cleveland, has been found hanged in his prison cell, the Ohio Department of Rehabilitation and Correction said in an email.

Castro, 53, was in a cell by himself in protective custody at the Correction Reception Center in Orient, Ohio, wrote JoEllen Smith with the state corrections agency.

Castro was found at 9:20 p.m. ET in the cell, where checks are required every 30 minutes, Smith wrote in the email.

"A thorough review of this incident is underway and more information can be provided as it becomes available pending the status of the investigation," she wrote.

Castro, a former Cleveland bus driver, was sentenced to life in prison plus 1,000 years on Aug. 1 related to the kidnapping, abuse and imprisonment for more than a decade of Amanda Berry, Gina DeJesus and Michelle Knight, who were held in chains. The case elicited emotions from people across the country whose hearts went out to the young women Castro pleaded guilty to kidnapping and abusing. Castro said he was not mean to the women during their captivity.

The women were captured between 2002 and 2004 and held until May 6, when Berry managed to escape and alert others.

Craig Weintraub, Castro's attorney, tells NBC's TODAY show Wednesday that his client's family was "devastated by the news."

He says relatives had visited Castro "a couple of time" since he was moved to the prison about two weeks ago.

The attorney says he realizes that many people will likely view Castro's death as"good riddance," but says he plans to "get to the bottom" of the circumstances surrounding his death. "This is a human being," he says.

Social media users reacted with anger and happiness to the news. On Twitter, users used the hashtag or search term #deadgiveaway to indicate they were tweeting about Castro.

One Twitter customer using the hashtag wrote: "Ariel Castro is gonna rot in hell."

According to his Ohio prison record, Castro was serving time for - among other charges - 473 counts of kidnapping, 446 counts of rape and one count of aggravated murder.

Amid cheers from onlookers, Castro's house was torn down last month by two demolition companies free of charge after Cuyahoga County prosecutor Tim McGinty said he wanted it razed so it would not become a macabre tourist attraction.